Question

Please answer all.

3) What is the probability of each of the following sets of parents producing the given genotypes in their

offspring?

Parents Offspring Probability

a. BBDD x BbDD BbDD

b. BbDd x BbDd BBDd

c. BbDd x bbDd BbDD

d. bbDd X BBdd bbdd

4) Duchenne muscular dystrophy is due to a sex-linked recessive gene. A normal male and a

normal female have children. Their first child (a boy) has Duchenne muscular dystrophy.

What are the possible genotypes of a second son (if they had one)?

What are the chances their third son, if they had one, would have the disorder?

What are the genotypes of the mother and the father?

5) In a species of frog the gene for color shows codominance. Frogs that are black and frogs that

are yellow are homozygous. Frog with one black allele and one yellow allele are black and

yellow (i.e. their skin is black with yellow spots). For each of the following construct a

Punnett square and give phenotypic and genotypes and the ratios of the offspring.

a) a yellow frog mates with a black frog
b) a yellow frog mates with a black and yellow frog (i.e. black frog with yellow spots)
c) a black frog mates with a black and yellow frog (i.e. black frog with yellow spots)
d) two black and yellow frogs

6) What are the odds of a couple having a child with blood type Bi if the mother’s blood type is

heterozygous for A and their father’s blood type is heterozygous for B?

7) For each phenotype determine the genotype.

Black spots are dominant to brown spots

Homozygous black _________

Brown spots __________

Long ears are dominant to short ears

Heterozygous ____________

Homozygous for long ears ____________

8) White pigmentation is recessive to red.

Rr x Rr - What percentage of the offspring will be red?________

Rr x rr - What percentage of the offspring will be white? _______